Driving and control device



Oct. 28, 1958 v F. RALL 2,857,768 v DRIVING Am CONTROL DEIICE INVENTOR:

. FELIX RALL 3 Sheets-Sheet l F 1 dAp i1 29 1955 AT TORNEYS Oct. 28,1958 F. RALL muvma AND CONTROL DEVICE 3 Sheets-Sheet 2 Filed April 29,1955 INVENTOR: FELIX RALL ATTORNEYS Oct. 28,1958 RALL 2,857,768

DRIVING AND CONTROL DEVICE Filed April 29, 1955 a Sheets-Shet s FELIXRALL INVEN TOR BY M/ wM/ ATTORNEYS United States Patent DRIVING ANDCONTROL DEVICE Felix Rall, Biel, Switzerland, assignor to Giesserei &ivlaschinenfabrik Osterwalder A. G., Biel, Switzer- Application April29, 1955, Serial No. 504,921

Claims priority, application Switzerland April 30, 1954 4 Claims. (Cl.74-40) The present invention relates to a driving and control device inmachines for the chipless deformation of workpieces, and moreparticularly for toggle presses.

It is an object of the present invention to provide a driving andcontrol device in such machines, which permits an increase in theefiiciency of such machines in that either the working rate i. e. thenumber of pieces produced per time unit, or the effective operating timeas compared with the total operating time may be increased, i. e theloss operating time of the machine reduced.

A further object of the present invention is the provision of such adriving and control device which is particularly adapted for use incombination with the reciprocating ram of a toggle press or the like.

A still further object of the invention is the provision of a drivingand control device in connection with the reciprocating ram of a togglepress, which permits variation of the time slope of motion and the timeslope of the pressure applied to said ram.

According to the invention the driving and control device comprises aram which is supported for longitudinal movement and is hingedly inoperative connection with a member movable under the influence of twosuperposed reciprocating components of motion one of which in its timeslope is variable with respect to the other component.

The invention will now be more particularly described by way of examplewith reference to the accompanying drawings, in which:

Fig. l is a longitudinal section through a driving and control devicefor a toggle press,

Figs. 2 to 4 are diagrammatic views of the device in various positionsof the ram, and

Fig. 5 is a view showing the slidably mounted gear and its position withthe other gears.

Fig. 1 shows the construction of the driving and control device. A ram 1supported for longitudinal movement is hingedly linked by means of a ramrod 2 with a toggle joint plate 3 which is pivotally mounted on astationary abutment 4. A link 5 is in hinged connection with the plate 3at one end, while at the other end it is rotatably mounted on the pivot6 of a connecting rod 7. The rod 7 is connected with a crank pin 8 of arotatably supported crankshaft 9 on which a gear 10 is firmly mounted.An additional connecting rod 11, which is rotatably supported on aneccentric 12, is linked to the pivot 6 of the connecting rod 7. Theeccentric 12 is positively interconnected for rotation with a shaft 13,a gear 14 meshing with the gear 10 and provided with the same number ofteeth being slidably mounted on the shaft 13. The gear 14, moreover,meshes with a gear 15 which is splined to the rotor shaft 16 of anelectromotor 17.

At the position of the members shown in Fig. 1, the ram 1 carries outits forward movement or its operative stroke according to the directionof rotation of the motor 17 indicated by the arrow 18. The motion of theram consists of two components, one of which is determined by theeccentricity of the crank pin 8 while the other component is determinedby the eccentricity of the eccentric 12. These two motions may be addedor subtracted depending on the mutual angular position of the twoeccentric members, which position may be varied by rotating the oneeccentric with respect to the other while the gears 14 and 10 are out ofengagement. the stroke of the ram may be varied within certain limits.

From the position indicated in Fig. 1, the crank pin 8 thus travelsdownwardly upon continued rotation of the gears 15, 14 and 10, so thatthe connecting rod 11 and link 5 approach more and more their alignedposition, that is the position in which their longitudinal axes willcoincide. From this straightening action there results an upwardrotation of the toggle joint plate 3 and thus a movement of the ram inthe forward direction. At the same time, however, the eccentric 12 orthe connecting rod 11, respectively, has passed through its rear deadcenter position and is now moved towards the left side by the movementof the eccentric, whereby an additional and simultaneous movement of theram in the same direction is effected by means of link 5, toggle jointplate 3, and ram rod 2.

In Fig. 2 the position of the individual members of the device is shownat the rear reversing point of the ram position, while Fig. 3 shows theposition of the members at the forward reversing point. In Fig. 4 theram is shown in a position midway of its stroke length. The parts shownin full line indicate the position of the latter when the center of thestroke length is passed during the return travel of the ram 1, while theparts shown by dash-and-dot lines show the position of the latter in thesame point of the stroke length but during the forward travel of theram. The rotary angle 01., in this case, provides a measure of theperiod of time for the forwardand return travel of the ram through thefront half of the stroke half at a constant speed of the gear 10.

From the magnitude of the angle designated by ,8, on the other hand, itmay be seen that the period of time required for the rear half of thestroke is considerably shorter, i. e. the so-called dead periods of timewill be very short for the forward travel as well as for the returntravel so that a correspondingly longer period of time is available forthe operative stroke of the ram.

However, not only the time slope of the motion but also the time slopeof the pressure provided on the ram will be influenced by the describeddevice since the pressure components of eccentric 12 and crank pin 8 areadded together in the same manner as the motional components thereof bya suitable angular adjustment of the eccentric 12 in respect to thecrank pin 8. Thereby it is possible to arrive earlier at the minimumworking pressure relative to the length of the stroke. The operativestroke thus is lengthened, which fact in turn means a prolongation ofthe operating time. Therefore it is possible, 'even with large operatingstrokes or in case of deformation work, to allow the material sufficienttime to flow so that it is nevertheless possible to operate with a verygreat number of strokes per time unit.

In addition it is possible to change the slope of motion and pressurenot only in respect to time but also in its magnitude by varying theeccentricities.

I claim:

1. A driving and control device comprising a ram arranged forlongitudinal reciprocatory movement, a toggle joint plate pivotallymounted on a support and pivotally linked to said ram, a pivot pivotallylinked with said toggle joint plate, two connecting rods hingedly 002;-

By this means nected to said pivot, two eccentrics and driving means forsaid eccentrics disengageable from said eccentrics for permittingadjustment of the eccentrics relative to each other, each of saideccentrics being engaged by one of said connecting rods and adapted tomove said pivot and impart a reciprocatory movement to said ram, as thesum of the superposed movements imparted to said pivot by both of saideccentrics.

2. A driving and control device comprising a ram supported forlongitudinal reciprocal movement, a toggle plate pivotally mounted on asupportand pivotally linked to said ram, two connecting rods pivotallyconnected to each other and an eccentric means driving each connectingrod, 2. link pivotally linking said toggle plate and said two connectingrods where they are pivoted to each other, and driving means for drivingsaid eccentric means.

i 3. A driving and control device as claimed in claim 2 in which saiddriving means comprise a shaft on which one of said eccentric means ismounted, a crankshaft operatively connected to said shaft for rotationtherewith, the eccentric on said crankshaft being a crank thereon, and amotor driving said shaft.

4. A driving and control device as claimed in claim 2 in which saiddriving means comprise a shaft on which one of said eccentric means ismounted, a crankshaft, a gear on said shaft, a gear on said crankshafthaving the same number of teeth as the gear on said shaft and beingmeshed therewith, the gear on said shaft being slidable on said shaft,the eccentric on said crankshaft being a crank thereon, and a motordriving said shaft, whereby said gear on said shaft may be disengagedfrom said gear on said crankshaft and said crankshaft rotated withrespect to said shaft for varying the position of one of two saidconnecting rods with respect to the other.

References Cited in the file of this patent UNITED STATES PATENTS480,737 Niemczyk Aug. 16, 1892 1,174,801 Babcock Mar. 7, 1916 2,035,222Curtis Mar. 24, 1936 FOREIGN PATENTS 522,792 Great Britain June 27, 1940

